scholarly journals Quantitative Delineation of the Low Energy Decomposition Pathway for Lithium Peroxide in Lithium–Oxygen Battery

2020 ◽  
Vol 7 (19) ◽  
pp. 2001660 ◽  
Author(s):  
Arghya Dutta ◽  
Kimihiko Ito ◽  
Akihiro Nomura ◽  
Yoshimi Kubo
Keyword(s):  
Low Energy ◽  
Energy Decomposition ◽  
Lithium Peroxide ◽  
Lithium Oxygen Battery ◽  
Decomposition Pathway

scholarly journals Sparse + low-energy decomposition for viscous conservation laws

2015 ◽  
Vol 288 ◽  
pp. 150-166 ◽  
Author(s):  
Thomas Y. Hou ◽  
Qin Li ◽  
Hayden Schaeffer
Keyword(s):  
Conservation Laws ◽  
Low Energy ◽  
Energy Decomposition ◽  
Viscous Conservation Laws

Lattice Boltzmann Simulation of Lithium Peroxide Formation in Lithium–Oxygen Battery

2016 ◽  
Vol 13 (3) ◽  
Author(s):  
M. Jithin ◽  
Malay K. Das ◽  
Ashoke De
Keyword(s):  
Porous Media ◽  
Lattice Boltzmann ◽  
Pore Scale ◽  
Peroxide Formation ◽  
Initial Current ◽  
Lattice Boltzmann Simulation ◽  
Lithium Peroxide ◽  
Lower Porosity ◽  
Lithium Oxygen Battery ◽  
Boltzmann Method

Present research deals with multiphysics, pore-scale simulation of Li–O2 battery using multirelaxation time lattice Boltzmann method. A novel technique is utilized to generate an idealized electrode–electrolyte porous media from the known macroscopic variables. Present investigation focuses on the performance degradation of Li–O2 cell due to the blockage of the reaction sites via Li2O2 formation. Present simulations indicate that Li–air and Li–O2 batteries primarily suffer from mass transfer limitations. The study also emphasizes the importance of pore-scale simulations and shows that the morphology of the porous media has a significant impact on the cell performance. While lower porosity provides higher initial current, higher porosity maintains sustainable output.

A high-energy-density lithium-oxygen battery based on a reversible four-electron conversion to lithium oxide

Science ◽  
2018 ◽  
Vol 361 (6404) ◽  
pp. 777-781 ◽  
Author(s):  
C. Xia ◽  
C. Y. Kwok ◽  
L. F. Nazar
Keyword(s):  
Energy Density ◽  
Coulombic Efficiency ◽  
Bond Cleavage ◽  
High Capacity ◽  
High Energy ◽  
High Energy Density ◽  
Lithium Oxide ◽  
Lithium Peroxide ◽  
Lithium Oxygen Battery ◽  
Electron Reduction

Lithium-oxygen (Li-O2) batteries have attracted much attention owing to the high theoretical energy density afforded by the two-electron reduction of O2 to lithium peroxide (Li2O2). We report an inorganic-electrolyte Li-O2 cell that cycles at an elevated temperature via highly reversible four-electron redox to form crystalline lithium oxide (Li2O). It relies on a bifunctional metal oxide host that catalyzes O–O bond cleavage on discharge, yielding a high capacity of 11 milliampere-hours per square centimeter, and O2 evolution on charge with very low overpotential. Online mass spectrometry and chemical quantification confirm that oxidation of Li2O involves transfer of exactly 4 e–/O2. This work shows that Li-O2 electrochemistry is not intrinsically limited once problems of electrolyte, superoxide, and cathode host are overcome and that coulombic efficiency close to 100% can be achieved.

scholarly journals Effect of Unwanted Guest Molecules on the Stacking Configuration of Covalent Organic Frameworks: A Periodic Energy Decomposition Analysis

2020 ◽  
Author(s):  
A.D. Dinga Wonanke ◽  
Mathew Addicoat
Keyword(s):  
Guest Molecule ◽  
Dispersion Model ◽  
Critical Role ◽  
Decomposition Analysis ◽  
Empirical Method ◽  
Low Energy ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Guest Molecules ◽  
Semi Empirical

Elucidating the precise stacking configuration of a covalent organic framework, COF, is critical to fully understand their various applications. Unfortunately, most COFs form powder crystals whose atomic characterisations are possible only through powder X-ray diffraction (PXRD) analysis. However, this analysis has to be coupled with computational simulations, wherein computed PXRD patterns for different stacking configurations are compared with experimental patterns to predict the precise stacking configuration. This task is often computationally challenging firstly because, computation of these systems mostly rely on the use of semi-empirical methods that need to be adequately parametrised for the system being studied and secondly because some of these compounds possess guest molecules, which are not often taken into account during computation. COF-1 is an extreme case in which the presence of the guest molecule plays a critical role in predicting the precise stacking configuration. Using this as a case study, we mapped out a full PES for the stacking configuration in the guest free and guest containing system using the GFN-xTB semi-empirical method followed by a periodic energy decomposition analysis using first principle DFT. Our results showed that the presence of the guest molecule leads to multiple low energy stacking configurations with significantly different lateral offsets. Also, the semi-empirical method does not precisely predict DFT low energy configurations, however, it accurately accounts for dispersion. Finally, our quantum-mechanical analysis demonstrates that electrostatic-dispersion model suggested Hunter and Sanders accurately describe the stacking in 2D COFs as oppose to the newly suggested Pauli-dispersion model.

Chemically synthesized lithium peroxide composite cathodes for closed system Li–O2 batteries

2016 ◽  
Vol 52 (33) ◽  
pp. 5678-5681 ◽  
Author(s):  
Amruth Bhargav ◽  
Wei Guo ◽  
Yongzhu Fu
Keyword(s):  
Closed System ◽  
Carbon Nanofiber ◽  
Composite Cathode ◽  
Nanofiber Composite ◽  
Lithium Peroxide ◽  
Composite Cathodes ◽  
Binder Free ◽  
Lithium Oxygen Battery

A binder-free lithium peroxide–carbon nanofiber composite cathode was synthesized chemically to be used in a closed system lithium–oxygen battery without external supply of oxygen.

scholarly journals Effect of Unwanted Guest Molecules on the Stacking Configuration of Covalent Organic Frameworks: A Periodic Energy Decomposition Analysis

2020 ◽  
Author(s):  
A.D. Dinga Wonanke ◽  
Mathew Addicoat
Keyword(s):  
Guest Molecule ◽  
Dispersion Model ◽  
Critical Role ◽  
Decomposition Analysis ◽  
Empirical Method ◽  
Low Energy ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Guest Molecules ◽  
Semi Empirical

Elucidating the precise stacking configuration of a covalent organic framework, COF, is critical to fully understand their various applications. Unfortunately, most COFs form powder crystals whose atomic characterisations are possible only through powder X-ray diffraction (PXRD) analysis. However, this analysis has to be coupled with computational simulations, wherein computed PXRD patterns for different stacking configurations are compared with experimental patterns to predict the precise stacking configuration. This task is often computationally challenging firstly because, computation of these systems mostly rely on the use of semi-empirical methods that need to be adequately parametrised for the system being studied and secondly because some of these compounds possess guest molecules, which are not often taken into account during computation. COF-1 is an extreme case in which the presence of the guest molecule plays a critical role in predicting the precise stacking configuration. Using this as a case study, we mapped out a full PES for the stacking configuration in the guest free and guest containing system using the GFN-xTB semi-empirical method followed by a periodic energy decomposition analysis using first principle DFT. Our results showed that the presence of the guest molecule leads to multiple low energy stacking configurations with significantly different lateral offsets. Also, the semi-empirical method does not precisely predict DFT low energy configurations, however, it accurately accounts for dispersion. Finally, our quantum-mechanical analysis demonstrates that electrostatic-dispersion model suggested Hunter and Sanders accurately describe the stacking in 2D COFs as oppose to the newly suggested Pauli-dispersion model.

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